Understanding and Improving the heater... Options

[Rod]

I have just replaced the heater blower and control panel on my 914 and the front trunk blower now works for the first time The previous owner to me covered over the dash vents with vinyl, so I have uncovered and trimmed around these too.

I have totally stripped out the interior, sorted any rust (er... none ) dynamatted the whole interior, put in extra soundproofing, fibreglassed over and repaired the back pad where the board/wood had perished and fitted a new grey loop carpet set from Appearance and Performance, phew. Looks fabulous and returning to perfect condition

Now as I understand it, the dashboard levers work like this...

1. Top lever

FRESH air vent and fan control

2. Middle Lever

Controls direction of FRESH air delivered by above lever (left footwell, right dashboard.)

3. Bottom Lever

Controls direction of HEAT from 4 below. (Again far left footwell, Right Dash vents)

4. Lever between seats

Controls rear fan and therefore HEAT into cabin.

So the front fan plays no part in heating the car whatsoever, just FRESH air.

HEAT is controlled directly by the lever between the seats (the direction of which is controlled by the 3rd land lowest lever on the control panel)

So, if I am correct with the above can you tell me why hot air only comes from the drivers side? It is really hot air on this side and blown with quite a force, yet the passenger side is cool.. I know there are differences between 73 and 74 cars in that the earlier cars (like mine) have a rear fan that only blows down the drivers side and later cars had a T piece which splits the air from the blower and connects to the passenger side, but is this why it is cold on the ps?? Surely it wasn't that bad from the factory in '73??

Long post sorry, but hopefully concise regarding my problem.. My wife is an Aussie and is complaining that she gets cold, so I'm determined to get more heat on her side if possible.

Cheers (IMG:style_emoticons/default/beerchug.gif)

[Gint]

You're pretty much correct and dash controls you've got down pat. But here's a some clarification and info.

Edit: And I realize now that I'm really only expounding on what Joe already wrote, but I typed all of this already before I read Joe's reply so here ya go!

The electric blower motor is very weak and only does any real good at idle or below 2 or 2.5k rpm anyway. Mine doesn't work and I don't even care. I wouldn't bother putting the extra hose over to the passenger side. Just drive faster... (IMG:style_emoticons/default/wink.gif)

Why?

The floor lever once opened even a little bit, starts to open the heater flapper valves. You don't need the electric motor at all to get heat blowing. But as I said before, it does help below a certain engine rpm.

Why?

Once you reach 2.5k rpm+, the engine cooling fan blows so much air through the HE's and flapper valves that it overcomes anything the electric blower motor can provide (as I said, it's very weak anyway). You've probably already noticed that there is much more air when you're operating the car with the motor at higher rpm's.

Also...

You have to open the floor lever all the way to engage the switch to turn on the electric blower motor BTW. At partial opening, the electric blower isn't turned on, but doesn't necessarily need to be.

If you have no warm air on the passenger side, it's because the flow of warm air from the HE's is either obstructed, or your ducting is not completely installed or rusted away and full of holes. Or the flapper valve is not opening, stuck, rusted away and full of holes. Or your HE's are blocked, or rusted and full of holes. Or any of the heater hoses coming from the rear of the car that carry warm air are missing, blocked or full of holes.

You're probably getting the idea. Good luck!

This post has been edited by Gint: Oct 11 2008, 08:22 PM